1. Technical Field
The present disclosure relates to illuminating devices and, particularly, to a light emitting diode (LED) illuminating device.
2. Description of Related Art
Compared to traditional illuminating devices, LED lights have many advantages such as high luminous efficiency, low radiation, power saving, long life, etc. Yet, LED lights still have disadvantages. Because light emitted by LEDs is directional, light divergence angle of the LED light is less than that of the traditional illuminating device. Referring to FIG. 13, the light divergence angle of the traditional light source is S1, the value of S1 is about 160 degrees. Referring to FIG. 14, the light divergence angle of an LED is S2, the value of S2 is about 60 degrees.
People have combined several LEDs in a single LED illuminating device to enlarge the light divergence angle of the LED illuminating device. Referring to FIG. 15, a ring shaped LED illuminating device using many substrates 10 is shown. Each substrate 10 carries LEDs 11. The light divergence angle of the LED illuminating device is enlarged, yet, more heat is produced by the LEDs 11 (shown as arrows) between the substrates 10, which makes the LED illuminating devices become too hot.
Thus, what is needed is a LED illuminating device with large light divergence angle and good heat dissipation ability.